There has been proposed a related-art image forming apparatus that includes a charger having a discharge wire (wire electrode) and a grid electrode and generating the corona discharge from the wire electrode in order to charge a surface of a photosensitive drum. In the related-art image forming apparatus, the charger is arranged such that the grid electrode (grid surface opposed to the photosensitive drum) is orthogonal to a plane including the wire electrode and a rotational center portion of the photosensitive drum.